springs and struts : Java Glossary

Vibe’s replacement technique for layouts that automatically adjusts the size
and position of the components to fit the amount of screen real estate provided.
Instead of writing code, you visually connect components with fixed length struts,
natural length struts and variable length springs. Natural sizes are important
because they define what the width and height naturally are for a widget as well as
the minimum distance between widgets. For example, on Windows 95 the natural size of
a button is 75 × 23 while on Motif it is 80x25. By
using a natural size, the developer does not have to worry about such details. Fixed
length struts can be used to control absolute positioning and also the minimum size
of various components.